MAT 122 Lecture Notes - Lecture 14: Identity Matrix, Nxp Semiconductors, Row And Column Vectors
Document Summary
Mat 122- lecture 14-addition, subtraction and multiplication of matrices. Dimensions: written: m x n, m = rows, n = columns, example: 4 5 2 7 1 (shows 5 columns) 4 5 2 7 1 (shows 2 rows) 9 2 1 (3x3: when m = n it is called a square", matrix with one row is called a row vector", matrix with one column is called a column vector". Equality: two matrices are considered equal if they have the same size and all corresponding entries are identical, example: Multiplication of matrices: multiplying a matrix by a scalar (= number, multiplying every entry of the matrix by that number, example: Size = 2x2 (1*-5)+(-2*7) (1*6)+(-2*-8) (-5+ -14) (6+16) (-3*-5)+(-3*7) (-3*6)+(4*-8) (15+ -21) (-18+ -32) *size = 2x2* (-5*1)+(-3*6) (-5*-2)+(6*4) (-5+ -18) (10+24) (7*1)+(-8*-3) (7*-2)+(-8*4) (7+ 24) (-14+ -32) *note that when multiplying ab ba* (only rarely) 6 7 (3x2) (3x3) (3x2) match size of new matrix.
